Rise of echinoderms in the Paleozoic evolutionary fauna: Significance of paleoenvironmental controls

Abstract

Research Article| May 01, 1992 Rise of echinoderms in the Paleozoic evolutionary fauna: Significance of paleoenvironmental controls Thomas E. Guensburg; Thomas E. Guensburg 1Physical Science Division, Rock Valley College, Rockford, Illinois 61111 Search for other works by this author on: GSW Google Scholar James Sprinkle James Sprinkle 2Department of Geological Sciences, University of Texas, Austin, Texas 78713-7909 Search for other works by this author on: GSW Google Scholar Author and Article Information Thomas E. Guensburg 1Physical Science Division, Rock Valley College, Rockford, Illinois 61111 James Sprinkle 2Department of Geological Sciences, University of Texas, Austin, Texas 78713-7909 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1992) 20 (5): 407–410. https://doi.org/10.1130/0091-7613(1992)020<0407:ROEITP>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Thomas E. Guensburg, James Sprinkle; Rise of echinoderms in the Paleozoic evolutionary fauna: Significance of paleoenvironmental controls. Geology 1992;; 20 (5): 407–410. doi: https://doi.org/10.1130/0091-7613(1992)020<0407:ROEITP>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Echinoderms were a major enduring component of Paleozoic marine faunas beginning with the rapid diversification of crinoids and other classes in the Early Ordovician. This diversification was triggered by increased availability of habitable areas accompanying sea-level rise and changed sedimentation styles. Newly collected Early Ordovician echinoderms facilitate determination in detail of life modes and important adaptations during this transition interval. Substrate consistency and stability were crucial spatial limiting factors that resulted in heterogeneous distribution patterns for echinoderm classes. Crinoids were overwhelmingly large-food-groove suspension feeders with relatively open filtration fans attached by small discs to hard-ground surfaces in shallow water. They were preadapted for this life mode. Rhombiferans were mobile small-food-groove suspension feeders; they lived on soft substrates at various depths. Several important crinoid clades underwent a second phase of diversification during the Middle Ordovician by developing holdfasts adapted to soft substrates and densely pinnulate arms with small food grooves, leading to dominance of this class among Paleozoic echinoderms. Our findings are in basic agreement with the overall onshore diversification pattern of most Paleozoic benthic invertebrates, but we argue for an extrinsic environmental control (substrate availability) for the observed echinoderm distribution. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.